A digital image is typically display or printed in the form of a rectangular array of “picture elements” or “print elements”. Both picture elements and print elements are often referred to as “pixels”. Digital images are typically represented in a computer by one or more arrays of binary numbers. For example, a monochrome digital image can be represented in a computer by a single array of binary numbers. Each binary number in the array defines a gray-level value for an associated pixel. The position of the binary number in the array describes a spatial location of the pixel.
A color digital image can be represented in a computer by three arrays of binary numbers. These arrays are commonly referred to as “image planes” that represent an axis of a suitable color coordinate system in accordance with well-known trichromatic theory. The color of a pixel in the digital image is defined by an associated binary number from each array that represents one of three color components from the color coordinate system. There are many color coordinate systems that can be used to represent the color of a pixel. These color coordinate systems include, for example, a “Red-Green-Blue” (RGB) coordinate system and a Cyan-Magenta-Yellow (CMY) coordinate system. The former is commonly used in monitor display applications, whereas the latter is commonly used in printing applications.
The amount of data used to represent a digital image can be extremely large. Consider, for example, a color digital image consisting of 1024×1024 pixels. If the pixels are represented in the computer by three image planes of 8-bit numbers, the digital image would occupy over 1 megabyte of storage space. The large amount of data required to represent a digital image in a computer can result in significant costs that are associated both with increased storage capacity requirements, and the computer resources and time required to transmit the data to another computing device such as a printer, etc.